In this specification geometrical terms such as "above" and "below" relate to the gravitational directions, "above" being further from the centre of the earth than "below".
Materials can be found in the solid, liquid and gaseous phases; at lower ambient temperatures and higher pressures the material tends towards the solid phase, and at higher temperatures and lower pressures the material tends towards the gaseous phase.
A condenser is employed to convert a gas (a material in its gaseous phase) into its liquid phase. As the gas is condensed, it gives off its latent heat of evaporation, warming the surrounding area, and also reducing in volume. Condensers are typically employed in power plants for the condensation of exhaust steam from turbines, and in refrigeration plants for the condensation of refrigerant vapours such as the Freons or ammonia. They are also employed in the petroleum and chemical industries for the condensation of hydrocarbons and other chemical vapours.